$ aptitude search xwiki | grep "^i"
i A xwiki-enterprise-common         - XWiki is a free wiki software platform wri
i A xwiki-enterprise-mysql-common   - XWiki is a free wiki software platform wri
i A xwiki-enterprise-tomcat-common  - XWiki is a free wiki software platform wri
i   xwiki-enterprise-tomcat7-mysql  - XWiki is a free wiki software platform wri

# apt-cache policy xwiki-enterprise-tomcat7-mysql identifies the installed version as 6.1
# and the candidate as 6.2

$ LANGUAGE=en_EN.UTF-8 apt-get upgrade
...
The following packages will be upgraded:
... xwiki-enterprise-common xwiki-enterprise-mysql-common xwiki-enterprise-tomcat-common xwiki-enterprise-tomcat7-mysql
...
Get:1 http://maven.xwiki.org/ stable/ xwiki-enterprise-tomcat7-mysql 6.2 [1.420 B]
Get:2 http://security.debian.org/ wheezy/updates/main libapt-pkg4.12 i386 0.9.7.9+deb7u4 [902 kB]
Get:3 http://maven.xwiki.org/ stable/ xwiki-enterprise-tomcat-common 6.2 [1.996 B]
Get:4 http://maven.xwiki.org/ stable/ xwiki-enterprise-mysql-common 6.2 [4.526 B]              
Get:5 http://maven.xwiki.org/ stable/ xwiki-enterprise-common 6.2 [204 MB] 
...
Preparing to replace xwiki-enterprise-tomcat7-mysql 6.1 (using .../xwiki-enterprise-tomcat7-mysql_6.2_all.deb) ...
Unpacking replacement xwiki-enterprise-tomcat7-mysql ...
[ ok ] Stopping Tomcat servlet engine: tomcat7.
[ ok ] Starting Tomcat servlet engine: tomcat7.
Preparing to replace xwiki-enterprise-tomcat-common 6.1 (using .../xwiki-enterprise-tomcat-common_6.2_all.deb) ...
Unpacking replacement xwiki-enterprise-tomcat-common ...
Preparing to replace xwiki-enterprise-mysql-common 6.1 (using .../xwiki-enterprise-mysql-common_6.2_all.deb) ...
Unpacking replacement xwiki-enterprise-mysql-common ...
Preparing to replace xwiki-enterprise-common 6.1 (using .../xwiki-enterprise-common_6.2_all.deb) ...
Unpacking replacement xwiki-enterprise-common ...
dpkg: warning: unable to delete old directory '/etc/xwiki/cache/jbosscache': Directory not empty
...
Setting up xwiki-enterprise-common (6.2) ...
Installing new version of config file /etc/xwiki/classes/META-INF/NOTICE ...
Installing new version of config file /etc/xwiki/version.properties ...

Configuration file `/etc/xwiki/xwiki.cfg'
 ==> Modified (by you or by a script) since installation.
 ==> Package distributor has shipped an updated version.
   What would you like to do about it ?  Your options are:
    Y or I  : install the package maintainer's version
    N or O  : keep your currently-installed version
      D     : show the differences between the versions
      Z     : start a shell to examine the situation
 The default action is to keep your current version.
*** xwiki.cfg (Y/I/N/O/D/Z) [default=N] ? N
Installing new version of config file /etc/xwiki/xwiki.properties ...
Setting up xwiki-enterprise-tomcat-common (6.2) ...
Setting up xwiki-enterprise-mysql-common (6.2) ...
dbconfig-common: writing config to /etc/dbconfig-common/xwiki.conf
dbconfig-common: flushing administrative password
allow xwiki user to create new databases
dpkg: error processing xwiki-enterprise-mysql-common (--configure):
 subprocess installed post-installation script returned error exit status 1
dpkg: dependency problems prevent configuration of xwiki-enterprise-tomcat7-mysql:
 xwiki-enterprise-tomcat7-mysql depends on xwiki-enterprise-mysql-common (= 6.2); however:
  Package xwiki-enterprise-mysql-common is not configured yet.

dpkg: error processing xwiki-enterprise-tomcat7-mysql (--configure):
 dependency problems - leaving unconfigured
Errors were encountered while processing:
 xwiki-enterprise-mysql-common
 xwiki-enterprise-tomcat7-mysql
E: Sub-process /usr/bin/dpkg returned an error code (1)